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    <script src="a.js"></script>
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        console.log('周长: ' + primeter(3))
        console.log('面积: ' + area(3))

        console.log('==== 闭包处理后 ====')
        console.log('周长: ' + a.primeter(3))
        console.log('面积: ' + b.area(3))
    </script>
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